Chinese consumers are spending billions of dollars for anything from diapers to diamonds on "Singles Day," billed as the worlds biggest one-day online shopping festival. Also known as "Double 11" for the November 11 date, the event launched in 2009 by China’s e-commerce giant Alibaba Group, which said that sales by the thousands of retailers on its platforms had exceeded 130 billion yuan ($20 billion) by early evening Saturday in a count that started at midnight Friday. Last year, sales on Alibabas platforms totaled over 120.7 billion yuan, a record for the company. By comparison, American shoppers last year spent more than $5 billion shopping online on Thanksgiving Day and Black Friday, according to Adobe, which tracks such data. Shoppers also spent $3.39 billion on Cyber Monday last year, the largest single online shopping day in the U.S., Adobe said. In China, Alibabas main rival, online retailer JD.com, said sales had topped $16.7 billion — though the tallies are not comparable because JD tracks transactions starting from Nov. 1 through to the actual day. Starting at midnight Friday, diamonds, Chilean frozen salmon, tires, diapers, beer, shoes, handbags, and appliances were shipped out from JD.coms distribution centers on trucks bound for deliveries across China. China is already the worlds largest e-commerce market and the share of online shopping that makes up all consumer spending grows every year. Boston Consulting Group forecasts online spending will rise by 20 percent a year, hitting $1.6 trillion by 2020, compared with 6 percent growth for off-line retail. "Singles Day" was begun by Chinese college students in the 1990s as a version of Valentines Day for people without romantic partners. But environmentalists accuse Alibaba and other e-tailers of fuelling a culture of excessive consumption and mountains of waste. Greenpeace said "Singles Day" deliveries last year created 130,000 tons of packaging waste -- less than 10 percent of which is recycled. It said e-commerce is actually more carbon-intensive than brick-and-mortar shopping, calling "Singles Day" a "disaster for the environment."